Forging, rolling, and drawing are important fields in non-chip metal forming. All lubricants necessary for these metal working techniques are intended to ease the processing methods and to help improve the manufactured working parts.
In the field of drawing, differences exist between press drawing, tube drawing, rod drawing, bar drawing, and wire drawing. In the field of press drawing, especially deep drawing of sheet metal is of interest with regard to lubrication. For example, soap solutions, water soluble oil emulsions with or without chemically active additives, dry soap films and phosphate coatings were proposed and employed as the drawing media (agents) in deep drawing. In tube and rod drawing, drawing oils, soaps, or drawing greases serve as the lubricants. In tube drawing, the selection of lubricants is dependent on the pretreatment of the tubes. The lubricants employed in wire drawing are, for instance, dry soap compounds, drawing agent solutions as emulsions with different emulsifiers and further additives, as well as drawing oils and drawing greases.
German Auslegeschrift No. 1,088,646 teaches the use of boric acid or boric acid compounds which comprise at least one free hydroxyl group at the boric atom, in equimolar mixture with natural or synthetic resins having one or more free carboxyl and/or hydroxyl groups, in a mineral oil as the drawing lubricants. Using this mixture, a drawing lubricant of improved pressure loading capacity is obtained.
According to the process disclosed in German Auslegeschrift No. 1,030,954, a light granular non-sticky lubricant is obtained for the use in lubricating metal prior to its forming, said lubricant being composed of a fatty acid, soda, sodium chloride, borax and water. In describing said invention it was indicated that a quick dissolving of said lubricant on account of its granular porous consistency and its small particle size may be accomplished only by using soda and not by introducing sodium hydroxide, much less by adding potash or potassium hydroxide.
It is the object of the present invention to check the existing bias as exemplified in the description of the afore-mentioned German Auslegeschrift and provide improved lubricants for non-chip metal forming.